/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkMSAN_DEFINED
#define SkMSAN_DEFINED

#include "include/private/base/SkAssert.h"

#include <cstddef>
#include <string.h>

// Typically declared in LLVM's msan_interface.h.  Easier for us to just re-declare.
extern "C" {
void __msan_check_mem_is_initialized(const volatile void *, size_t);
void __msan_unpoison(const volatile void *, size_t);
}

// Code that requires initialized inputs can call this to make it clear that
// the blame for use of uninitialized data belongs further up the call stack.
static inline void sk_msan_assert_initialized(const void *begin, const void *end)
{
#if defined(__has_feature)
#if __has_feature(memory_sanitizer)
    __msan_check_mem_is_initialized(begin, (const char *)end - (const char *)begin);
#endif
#endif
}

// Lie to MSAN that this range of memory is initialized.
// This can hide serious problems if overused.  Every use of this should refer to a bug.
static inline void sk_msan_mark_initialized(const void *begin, const void *end, const char *skbug)
{
    SkASSERT(skbug && 0 != strcmp(skbug, ""));
#if defined(__has_feature)
#if __has_feature(memory_sanitizer)
    __msan_unpoison(begin, (const char *)end - (const char *)begin);
#endif
#endif
}

#endif // SkMSAN_DEFINED
